Border officials in the UK are preparing to go on strike over the government’s plans to turn back dinghies in the English Channel to counter a record number of crossings, as controversy grows over government proposals for handling migrants. A union that represents 80 per cent of border staff that would carry out the so-called pushbacks said they may go on strike even if they lose legal action against the proposed tactic. The government continues to consider various options to tackle the issue and has invited businesses to a meeting in the hope of hearing “innovative ideas” to limit the crossings. Home Secretary Priti Patel has also asked scientific advisers about using X-rays and other medical checks on asylum seekers to stop what she described as grown men “masquerading as children” on their applications. Migrant Watch — a think tank opposed to mass immigration — said in a report last week based on government figures that more than 1,100 adults falsely claimed to be children in the year to September 2021. In two thirds of cases where age was an issue, migrants were found to be adults. The Public and Commercial Services Union (PCS) and a charity have brought the legal action against the tactic that is part of a planned law intended to cut the record number of more than 28,000 people who made the perilous crossing from northern Europe last year. That figure was more than three times that of the previous year and continued through colder winter months across one of the world’s busiest shipping lanes. The government has tried — and failed — for several years to limit the numbers crossing the waterway by striking deals with France to improve security on its northern beaches and target people-smuggling gangs. The PCS says the pushback tactic puts lives at risk, contravenes international laws and is “morally reprehensible” by denying asylum seekers the opportunity to launch their claims in the UK. PCS general secretary Mark Serwotka said the policy could put border officials in danger of prosecution. “The legality of the pushbacks policy is in serious question, and it is right that the court decides whether it is unlawful to turn back Channel boats. “We cannot have a situation where our members could be open to potential civil and criminal action for implementing a policy that they do not agree with and know is not safe. “Although we are hoping for a positive outcome from the legal proceedings, people should be in no doubt PCS strongly opposes this policy, on moral and humanitarian grounds, and we will not rule out industrial action to prevent it being carried out.” Ms Patel said that pushbacks would only be considered under certain criteria including for the boat to be in a narrowly defined strip of waterway between France and the UK and with a French vessel close by. But experts have said any legal challenge against the pushback policy is likely to be successful. Lawyers have told Ms Patel’s department that the chances of successfully defending legal action are likely to be less than 30 per cent, leaked documents showed. Despite Ms Patel's pledge to make crossings an “infrequent phenomenon” by the spring of 2020, more than 36,000 people have succeeded in reaching the UK in the last two years. A Home Office representative said: “As part of our ongoing operational response and to prevent further loss of life at sea, we continue to test a range of safe and legal options to stop small boats making this dangerous and unnecessary journey. “These all comply and are delivered in accordance with both domestic and international law.” Downing Street was unable to say whether the number of small boats crossing the Channel this year will be lower than 2021's total. The prime minister's official spokesman said: “I'm not going to get into predictions over the level of crossings.” Officials said that any new deal with France was unlikely to happen before presidential elections in April with Emmanuel Macron seeking a new term. The two countries clashed in the aftermath of the deaths of 27 people when a dinghy capsized in November, with the French leader reportedly describing his counterpart Boris Johnson as a “clown”.